The following projects are being undertaken in collaboration with Pakistani and third country scientists: 1) Mosquito and disease ecology and genetic control. 2) Genetic studies to control Anopheles culicifacies. 3) Genetic control of Anopheles stephensi. Particular emphasis is placed on developing new biological methods to control those arthropod species that transmit human pathogens. Genetic manipulation of vector mosquito species has been developed to the stage where field release trials of laboratory reared populations, carrying deleterious genes are currently in progress.